<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
</html>
<script>
    var obj = {};
    obj.name = "zhangsan";
    obj.age = 13;
    obj.sex = "f";
    console.log(Object.keys(obj))
</script>